Distributed cellular systems, in which a central processing unit controls a number of distributed cells or remote radio units are becoming increasingly popular. Two examples of such systems are distributed antenna systems (DAS) and future cloud RAN (radio access network).
Distributed antenna systems (DAS) are being developed for the latest LTE (long term evolution) systems to improve cell coverage and system performance, by introducing a new network architecture in which multiple antennas are deployed over the cell in a distributed manner. In such an architecture, the antennas are connected to a central control hub unit (HU) normally with optical fibre and the antenna can be considered as radio remote units (RU), while the baseband signals are gathered and processed in the HU. As a result, the DAS can make use of spatial multiplexing gain and hence provide better system performance.
DAS can be deployed for different application scenarios. For example, the macro base station can be equipped with distributed antennas at different locations within a macro cell, instead of traditional co-located antennas. More recently, hybrid or heterogeneous networks are becoming more practical to address the coverage problem, offload the traffic, and improve user device experience. In such networks, different types of cells overlay the same area, for example, small pico cells sit within a macrocell. Normally these small cells are located indoors/inside a building and DAS are extremely useful for further improving the performance of these small cells. Therefore, DAS are becoming increasingly popular in buildings with such small cells.
Embodiments described herein may provide a novel resource allocation method for distributed cellular systems, where a central processing unit controls a number of distributed cells or remote radio units. These remote units can be, for example, RUs in a DAS architecture or remote radio units (RRUs) in the CRAN model.